Lighting control device for controlling dimming, lighting device including a control device, and method of controlling lighting

Abstract

A lighting control circuit comprises a dimming level detection circuit, a waveform generator and a comparator circuit. The dimming level detection circuit is configurable to generate a first voltage level signal corresponding to a selected one of at least two different types of dimming signals selected from among an AC phase cut dimming signal, a DC voltage level dimming signal or a PWM dimming signal. The waveform generator is configured to output a periodic waveform. The comparator circuit is configured to compare the periodic waveform with the first voltage level signal to generate an output waveform having a duty cycle corresponding to a dimming level of the one of the at least two different input dimming signals and a frequency corresponding to the frequency of the periodic waveform. Also, methods of controlling lighting.

That which is claimed is: 
     
       1. A lighting control circuit comprising:
 a dimming level detection circuit configurable to generate a first voltage level signal corresponding to a selected one of at least two different types of dimming signals, the types of dimming signals comprising at least two of an alternating current (AC) phase cut dimming signal, a direct current (DC) voltage level dimming signal or a pulse-width modulated (PWM) dimming signal; 
 a waveform generator configured to output a waveform generator periodic waveform; and 
 a comparator circuit configured to compare the waveform generator periodic waveform with the first voltage level signal to generate a comparator waveform having a comparator duty cycle corresponding to a dimming level of the one of the at least two different input dimming signals and a frequency corresponding to a frequency of the waveform generator periodic waveform. 
 
     
     
       2. A lighting control circuit as recited in  claim 1 , wherein the dimming level detection circuit is user configurable to generate the voltage level from one of the at least two different input dimming signals. 
     
     
       3. A lighting control circuit as recited in  claim 1 , wherein the dimming level detection circuit is preconfigured to generate the voltage level from one of the at least two different input dimming signals. 
     
     
       4. A lighting control circuit as recited in  claim 1 , wherein the dimming level detection circuit is configurable by electrical jumper configuration. 
     
     
       5. A lighting control circuit as recited in  claim 1 , wherein the dimming level detection circuit is configurable by component selection. 
     
     
       6. A lighting control circuit as recited in  claim 1 , wherein the dimming level detection circuit is configurable by connection to different input connectors associated with the at least two different types of dimming signals. 
     
     
       7. A lighting control circuit as recited in  claim 1 , wherein the lighting control circuit further comprises a shutdown comparator circuit which is configured to compare the first voltage level signal with a shutdown threshold voltage and to generate a shutdown signal based on the comparison. 
     
     
       8. A lighting control circuit as recited in  claim 1 , wherein the dimming level detection circuit comprises a wired OR circuit of voltage levels corresponding to the at least two different types of dimming signals. 
     
     
       9. A lighting control circuit as recited in  claim 1 , wherein the dimming level detection circuit comprises a duty cycle detection circuit and an averaging circuit. 
     
     
       10. A lighting control circuit as recited in  claim 9 , wherein the averaging circuit comprises a first averaging circuit configured to average a detected duty cycle of an AC dimming signal and a second averaging circuit configured to average a duty cycle of a PWM dimming signal. 
     
     
       11. A lighting device comprising:
 at least one solid state light emitter; 
 a lighting control circuit as recited in  claim 1 ; and 
 a driver circuit configured to vary the intensity of output of the at least one solid state light emitter in response to the comparator waveform. 
 
     
     
       12. A lighting device comprising:
 at least one solid state light emitter; 
 a lighting control circuit as recited in  claim 1 ; and 
 means for varying the intensity of output of the at least one solid state light emitter in response to the comparator waveform. 
 
     
     
       13. A lighting control circuit comprising:
 means for generating a first voltage level signal corresponding to a selected one of at least two different types of dimming signals, the types of dimming signals comprising at least two of an alternating current (AC) phase cut dimming signal, a direct current (DC) voltage level dimming signal or a pulse-width modulated (PWM) dimming signal; 
 means for generating a waveform generator periodic waveform; and 
 means for comparing the waveform generator periodic waveform with the first voltage level signal to generate a comparator waveform having a comparator duty cycle corresponding to a dimming level of the selected one of at least two different types of dimming signals and a frequency corresponding to a frequency of the waveform generator periodic waveform. 
 
     
     
       14. A lighting control circuit as recited in  claim 13 , wherein the lighting control circuit further comprises means for comparing the first voltage level signal with a shutdown threshold voltage and generating a shutdown signal based on the comparison. 
     
     
       15. A method of controlling lighting, comprising:
 generating a first voltage level signal based on a selected one of at least two different types of dimming signals, the types of dimming signals comprising at least two of an alternating current (AC) phase cut dimming signal, a direct current (DC) voltage level dimming signal or a pulse-width modulated (PWM) dimming signal; 
 generating a waveform generator periodic waveform; and 
 comparing the waveform generator periodic wavefonn with the first voltage level signal to generate a comparator waveform having a comparator duty cycle corresponding to a dimming level of the one of the at least two different input dimming signals and a frequency corresponding to a frequency of the waveform generator periodic waveform. 
 
     
     
       16. A method as recited in  claim 15 , further comprising:
 obtaining user input to identify the selected one of at least two different types of dimming signals. 
 
     
     
       17. A method as recited in  claim 15 , further comprising preconfiguring the selected one of the at least two different input dimming signals. 
     
     
       18. A method as recited in  claim 15 , further comprising setting an electrical jumper to identify the selected one of at least two different types of dimming signals. 
     
     
       19. A method as recited in  claim 15 , further comprising selecting components for a voltage generation circuit based on the selected one of at least two different types of dimming signals. 
     
     
       20. A method as recited in  claim 15 , wherein generating a first voltage level comprises generating a first voltage level based on a presence of a connection to different input connectors associated with the at least two different types of dimming signals. 
     
     
       21. A method as recited in  claim 15 , further comprising comparing the first voltage level signal with a shutdown threshold voltage and generating a shutdown signal based on the comparison. 
     
     
       22. A method as recited in  claim 15 , wherein voltage levels corresponding to the at least two different types of dimming signals are logically OR wired. 
     
     
       23. A method as recited in  claim 15 , wherein generating a first voltage level comprises:
 if the selected one of the at least two different dimming signals comprises AC dimming:
 detecting the duty cycle of the detected AC dimming signal; and 
 averaging the detected duty cycle of the AC dimming signal to provide the first voltage level; and 
 
 if the selected one of the at least two different dimming signals comprises PWM dimming, averaging the PWM dimming signal to provide the first voltage level. 
 
     
     
       24. A lighting control circuit comprising:
 a dimming level detection circuit, 
 a waveform generator; and 
 a comparator circuit, 
 the dimming level detection circuit configured to generate voltage level signals based on received input dimming signals of at least two types selected from among (1) phase cut AC type dimming signals, (2) voltage level type dimming signals and (3) PWM type dimming signals, 
 the waveform generator configured to output a waveform generator periodic waveform, and 
 the comparator circuit configured to generate a comparator waveform having (a) a comparator duty cycle based on a proportion of time during which an instantaneous voltage of the voltage level signals exceeds an instantaneous voltage level of the waveform generator periodic waveform, and (b) a frequency corresponding to a frequency of the waveform generator periodic waveform. 
 
     
     
       25. A lighting control circuit as recited in  claim 24 , wherein the dimming level detection circuit is configured to generate voltage level signals based on received input dimming signals of (1) phase cut AC type dimming signals, (2) voltage level type dimming signals and (3) PWM type dimming signals. 
     
     
       26. A lighting control circuit as recited in  claim 24 , wherein the dimming level detection circuit is configured to generate voltage level signals based on received input dimming signals of voltage level type dimming signals and PWM type dimming signals. 
     
     
       27. A lighting control circuit as recited in  claim 24 , wherein the dimming level detection circuit is configured to generate voltage level signals based on received input dimming signals of phase cut AC type dimming signals and PWM type dimming signals. 
     
     
       28. A lighting control circuit as recited in  claim 24 , wherein the dimming level detection circuit is configured to generate voltage level signals based on received input dimming signals of phase cut AC type dimming signals and voltage level type dimming signals. 
     
     
       29. A lighting control circuit as recited in  claim 24 , wherein the duty cycle of the comparator waveform generated by the comparator circuit is proportional to a proportion of time during which the instantaneous voltage of the voltage level signals exceeds the instantaneous voltage level of the waveform generator periodic waveform. 
     
     
       30. A lighting control circuit as recited in  claim 24 , wherein the duty cycle of the comparator waveform generated by the comparator circuit is inversely proportional to a proportion of time during which the instantaneous voltage of the voltage level signals exceeds the instantaneous voltage level of the waveform generator periodic waveform.